让同一个人两次响应，如何从数据库中删除 1 ......帮助真的卡住了

Question

我已经完成了下面一些人所说的，但现在我得到了一个错误代码：2067 (SQLITE_CONSTRAINT_UNIQUE) Caused By：由于违反约束而中止。（唯一约束失败：employees.Employee_number（代码 2067））

我在

的 EMployeeDBHandler 上收到此错误

database.insertWithOnConflict(TABLE_EMPLOYEE, null, values, 0);

我正在解析 Web 服务响应并将其存储到 SQLite 数据库中。一切都很好地加载到数据库中。我运行遇到的问题是我希望能够删除与另一行相同的行中的 1 行。我制作了 uniqueID 以便它可以存储到数据库中。

我怎样才能删除其中一条与另一条相同的记录？然后将仍然存在的那个拿走并移到另一个列表中？我正在使用 employeeNumber 进行网络呼叫，并希望将与该 employeeNumber 相关联的那个人放在自己的列表视图中，而响应中的其他所有内容都放在另一个列表中。

public class MainActivity extends AppCompatActivity {

    private ListView mTopList, mDirectReportList;
    private ProgressBar mProgressBar;
    private ArrayList<Employee> mEmployees = new ArrayList<>();
    private BottomListViewAdapter mBottomListViewAdapter;
    EmployeeDBHandler dbHandler;
    SQLiteDatabase db;
    SimpleCursorAdapter simpleCursorAdapter;
    private String startingEmployeeID = startingEmployeeNumber;
    private String table = "employees";
    private static final String KEY_ID = "Employee_number";


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        dbHandler = new EmployeeDBHandler(getApplicationContext());
        mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
        mProgressBar.setVisibility(View.VISIBLE);
    //    mBottomListViewAdapter = new BottomListViewAdapter(this, mEmployees);
    //    directReportListView.setAdapter(mBottomListViewAdapter);
        getXMLData();

        displayBottomList();

        // displayTopList(startingEmployeeID);

        //displayTopList();


        //GUI for seeing android SQLite Database in Chrome Dev Tools
        Stetho.InitializerBuilder inBuilder = Stetho.newInitializerBuilder(this);
        inBuilder.enableWebKitInspector(Stetho.defaultInspectorModulesProvider(this));
        Stetho.Initializer in = inBuilder.build();
        Stetho.initialize(in);


    }

    public void getXMLData() {
        OkHttpClient client = getUnsafeOkHttpClient();
        Request request = new Request.Builder()
                .url(getString(R.string.API_FULL_URL))
                .build();
        client.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                e.printStackTrace();
            }

            @Override
            public void onResponse(Call call, final Response response) throws IOException {
                final String responseData = response.body().string();
                final InputStream stream = new ByteArrayInputStream(responseData.getBytes());
                final XMLPullParserHandler parserHandler = new XMLPullParserHandler();
                final ArrayList<Employee> employees = (ArrayList<Employee>) parserHandler.parse(stream);

                for (Employee e : employees) {
                     dbHandler.addEmployee(e);

                }

                /*mEmployees.clear();
                mEmployees.addAll(employees);*/

                //tell adapter on the UI thread its data changed
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        /*mBottomListViewAdapter.notifyDataSetChanged();
                        directReportListView.setVisibility(View.VISIBLE);*/
                        mProgressBar.setVisibility(View.GONE);
                    }
                });
            }
        });
    }

    public void displayBottomList() {
        EmployeeDBHandler handler = new EmployeeDBHandler(this);
        SQLiteDatabase db = handler.getWritableDatabase();
        db.rawQuery("DELETE FROM " + table + " WHERE " + "Employee_number" + " EQUALS " + "Employee_number" + ");", null);
        Cursor mBottomListCursor = db.rawQuery("SELECT * FROM employees", null);

        ListView mBottomListView = (ListView) findViewById(R.id.mDirectReportList);
        BottomListViewAdapter bottomAdapter = new BottomListViewAdapter(this, mBottomListCursor);
        mBottomListView.setAdapter(bottomAdapter);
    }
}

现在，如果我不尝试执行删除查询，displayBottomList 方法可以工作，但问题是 startingEmpoyee 有两条记录，我删除了一条，然后删除保留在数据库中的 1 并将其移动到它自己的列表视图。

这是我在 displayBottomList

中的删除查询中收到的错误

错误代码：1 (SQLITE_ERROR) 原因：SQL(query) 错误或缺少数据库。（"EQUALS" 附近：语法错误（代码 1）：，编译时：DELETE FROM employees WHERE Employee_number EQUALS Employee_number);）

甚至可以删除重复项并删除另一行以填充新的列表视图吗？

public class EmployeeDBHandler extends SQLiteOpenHelper {
    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "OneTeam";
    private static final String TABLE_EMPLOYEE = "employees";

    //Employee table columns names
    private static final String KEY_ID = "Employee_number";
    private static final String KEY_FIRST_NAME = "First_name";
    private static final String KEY_LAST_NAME = "Last_name";
    private static final String KEY_PHONE_NUMBER_MOBILE = "Phone_mobile";
    private static final String KEY_PHONE_NUMBER_OFFICE = "Phone_office";
    private static final String KEY_PAYROLL_TITLE = "Payroll_title";
    private static final String KEY_HAS_DIRECT_REPORTS = "Has_direct_reports";
    private static final String KEY_EMAIL = "Email";
    private static final String KEY_COST_CENTER = "Cost_center_id";
    private static final String KEY_THUMBNAIL_IMAGE = "ThumbnailData";
    private final static String DB_CLIENTS_ID = "_id";


    public EmployeeDBHandler(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);

    }

    @Override
public void onCreate(SQLiteDatabase db) {
    String CREATE_EMPLOYEE_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_EMPLOYEE + "("
            + DB_CLIENTS_ID + " INTEGER PRIMARY KEY,"
            + KEY_ID + " TEXT,"
            + KEY_FIRST_NAME + " TEXT,"
            + KEY_LAST_NAME + " TEXT,"
            + KEY_PHONE_NUMBER_MOBILE + " TEXT,"
            + KEY_PHONE_NUMBER_OFFICE + " TEXT,"
            + KEY_PAYROLL_TITLE + " TEXT,"
            + KEY_HAS_DIRECT_REPORTS + " TEXT,"
            + KEY_EMAIL + " TEXT,"
            + KEY_THUMBNAIL_IMAGE + " TEXT,"
            + KEY_COST_CENTER + " TEXT"
            + "UNIQUE(" + KEY_ID + ")"
            + ")";
    db.execSQL(CREATE_EMPLOYEE_TABLE);
}

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        //drop old table if existence
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_EMPLOYEE);

        //Create table again
        onCreate(db);
    }

    //Add new employee
    public boolean addEmployee(Employee employee) {
        SQLiteDatabase database = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(KEY_ID, employee.getEmployee_number());
        values.put(KEY_FIRST_NAME, employee.getFirst_name());
        values.put(KEY_LAST_NAME, employee.getLast_name());
        values.put(KEY_PHONE_NUMBER_MOBILE, employee.getPhone_mobile());
        values.put(KEY_PHONE_NUMBER_OFFICE, employee.getPhone_office());
        values.put(KEY_HAS_DIRECT_REPORTS, employee.getHas_direct_reports());
        values.put(KEY_EMAIL, employee.getEmail());
        values.put(KEY_COST_CENTER, employee.getCost_center_id());
        values.put(KEY_PAYROLL_TITLE, employee.getPayroll_title());
        values.put(KEY_THUMBNAIL_IMAGE, employee.getThumbnailData());


        //Inserting Row
        database.insertWithOnConflict(TABLE_EMPLOYEE, null, values, 0);
        database.close();
        return true;
    }

    //Get single employee
    public Employee getEmployee(int employeeNumber) {
        SQLiteDatabase database = this.getReadableDatabase();
        Employee employee = null;

        Cursor cursor = database.query(TABLE_EMPLOYEE, new String[] {
                KEY_ID, KEY_FIRST_NAME, KEY_LAST_NAME, KEY_PHONE_NUMBER_OFFICE, KEY_PHONE_NUMBER_MOBILE,
                KEY_HAS_DIRECT_REPORTS, KEY_EMAIL, KEY_COST_CENTER, KEY_PAYROLL_TITLE, KEY_THUMBNAIL_IMAGE}, KEY_ID + "=?",
                new String[]{ String.valueOf(employeeNumber)}, null, null, null, null);
        if(cursor != null) {
            if(cursor.moveToFirst()) {
                employee = new Employee(cursor.getString(0),
                        cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4),
                        cursor.getString(5), cursor.getString(6), cursor.getString(7), cursor.getString(8),
                        cursor.getString(9), cursor.getString(10), cursor.getString(11), cursor.getString(12),
                        cursor.getString(12), cursor.getString(14), cursor.getString(15), cursor.getString(16),
                        cursor.getString(17), cursor.getString(18), cursor.getString(19), cursor.getString(20),
                        cursor.getString(21), cursor.getString(22), cursor.getString(23), cursor.getString(24),
                        cursor.getString(24), cursor.getString(25), cursor.getString(26));
            }
        }
            cursor.close();
            database.close();
            return employee;

    }

    //Get All Employees
    public ArrayList<Employee> getAllEmployees() {
        ArrayList<Employee> employeeList = new ArrayList<>();
        //Select all query
        String selectQuery = "SELECT * FROM " + TABLE_EMPLOYEE;

        SQLiteDatabase database = this.getWritableDatabase();
        Cursor cursor =  database.rawQuery(selectQuery, null);

        //looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                Employee employee = new Employee();
                employee.setEmployee_number(cursor.getString(cursor.getColumnIndex(KEY_ID)));
                employee.setFirst_name(cursor.getString(cursor.getColumnIndex(KEY_FIRST_NAME)));
                employee.setLast_name(cursor.getString(cursor.getColumnIndex(KEY_LAST_NAME)));
                employee.setPhone_office(cursor.getString(cursor.getColumnIndex(KEY_PHONE_NUMBER_MOBILE)));
                employee.setPhone_mobile(cursor.getString(cursor.getColumnIndex(KEY_PHONE_NUMBER_OFFICE)));
                employee.setHas_direct_reports(cursor.getString(cursor.getColumnIndex(KEY_HAS_DIRECT_REPORTS)));
                employee.setEmail(cursor.getString(cursor.getColumnIndex(KEY_EMAIL)));
                employee.setCost_center_id(cursor.getString(cursor.getColumnIndex(KEY_COST_CENTER)));
                employee.setPayroll_title(cursor.getString(cursor.getColumnIndex(KEY_PAYROLL_TITLE)));
                employee.setThumbnailData(cursor.getString(cursor.getColumnIndex(KEY_THUMBNAIL_IMAGE)));
            } while (cursor.moveToNext());
        }

        //return employees list
        return employeeList;
    }

    //Get Employee Count
    public int getEmployeeCount() {
        String countQuery = "SELECT * FROM " + TABLE_EMPLOYEE;
        SQLiteDatabase database = this.getReadableDatabase();
        Cursor cursor = database.rawQuery(countQuery, null);
        cursor.close();

        return cursor.getCount();
    }

    //Updating single employee
    public int updateEmployee(Employee employee){
        SQLiteDatabase database = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_FIRST_NAME, employee.getFirst_name());
        values.put(KEY_LAST_NAME, employee.getLast_name());
        values.put(KEY_PHONE_NUMBER_MOBILE, employee.getPhone_mobile());
        values.put(KEY_PHONE_NUMBER_OFFICE, employee.getPhone_office());
        values.put(KEY_HAS_DIRECT_REPORTS, employee.getHas_direct_reports());
        values.put(KEY_EMAIL, employee.getEmail());
        values.put(KEY_COST_CENTER, employee.getCost_center_id());
        values.put(KEY_PAYROLL_TITLE, employee.getPayroll_title());
        values.put(KEY_THUMBNAIL_IMAGE, employee.getThumbnailData());

        return database.update(TABLE_EMPLOYEE, values, KEY_ID + " = ?",
                new String[] {String.valueOf(employee.getEmployee_number())});
    }

    //Delete single employee
    public void deleteEmployee(Employee employee) {
        SQLiteDatabase database = this.getWritableDatabase();
        database.delete(TABLE_EMPLOYEE, KEY_ID + " = ?",
                new String[] {String.valueOf(employee.getEmployee_number())});
        database.close();
    }

    //delete row
    public void delete(int id) {
        SQLiteDatabase db = this.getWritableDatabase();
        if (db == null) {
            return;
        }
        db.delete(TABLE_EMPLOYEE, "Employee+number = ?", new String[] { String.valueOf(id) });
        db.close();
    }
}

Answer 1

您的查询不正确 ` db.rawQuery("DELETE FROM " + table + " WHERE " + "Employee_number" + " EQUALS " + "Employee_number" + ") ;", 空);

您可以改用 check this link

Also check this link which is more suggested way of doing db operations

Answer 2

首先，如果您不想在 table 中插入重复条目，请像这样将 unique 约束添加到 table。

 @Override
public void onCreate(SQLiteDatabase db) {
    String CREATE_EMPLOYEE_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_EMPLOYEE + "("
            + DB_CLIENTS_ID + " INTEGER PRIMARY KEY,"
            + KEY_ID + " TEXT,"
            + KEY_FIRST_NAME + " TEXT,"
            + KEY_LAST_NAME + " TEXT,"
            + KEY_PHONE_NUMBER_MOBILE + " TEXT,"
            + KEY_PHONE_NUMBER_OFFICE + " TEXT,"
            + KEY_PAYROLL_TITLE + " TEXT,"
            + KEY_HAS_DIRECT_REPORTS + " TEXT,"
            + KEY_EMAIL + " TEXT,"
            + KEY_THUMBNAIL_IMAGE + " TEXT,"
            + KEY_COST_CENTER + " TEXT" +
            + "UNIQUE("+KEY_ID+")"+
          ")";
    db.execSQL(CREATE_EMPLOYEE_TABLE);
}

然后在插入时使用 insertWithOnConflict 而不是 insert。

这将忽略要插入到 table 中的重复条目。

其次，您当前的实施存在以下问题：

您应该在 onResponse 中调用 displayBottomList() 方法，因为响应会延迟，您应该在响应到来后才填充。
查询"DELETE FROM "+table+"WHERE"+"Employee_number"+"EQUALS"+"Employee_number"+");"将删除 table 的所有记录。我不知道你为什么要那样做。

Answer 3

您的代码几乎没有不相关的问题。首先，您正在 UI 线程上进行数据库查询，这是一个很大的问题。尝试卸载到后台线程。此外，您的 UI 数据可能不会在 Web 服务调用完成后得到更新（由其他答案之一指出）。这可以通过多种方式处理。现在谈到您的重复行问题，您可以通过多种方式处理它。

插入时忽略重复项。之前的一个回答提到了它。通过这个 link - https://sqlite.org/lang_conflict.html 基本上，您可以在 table 创建命令或 INSERT 命令中使用 ON CONFLICT 子句。无论哪种方式，它都会起作用。由于您似乎想忽略重复项，因此请使用 IGNORE 解析算法。
无需实际删除重复项即可使用的另一种方法是在查询中使用 GROUP BY 子句。这对您来说会更容易，因为您不必对当前架构和 INSERT 命令进行任何更改。只需在查询中使用 GROUP BY。检查此 link 如何使用 GROUP BY - https://www.sqlite.org/lang_select.html

您必须根据您的唯一键（在您的情况下为员工 ID）进行 GROUP BY。

让同一个人两次响应，如何从数据库中删除 1 ......帮助真的卡住了

Getting same person twice in response, how to delete 1 from database...Help really stuck

android

android-sqlite

android-cursoradapter